1 | /* |
2 | * Copyright (C) 2015, 2016 Apple Inc. All rights reserved. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions |
6 | * are met: |
7 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
14 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
15 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
17 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
18 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
19 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
20 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
21 | * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
23 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
24 | */ |
25 | |
26 | #pragma once |
27 | |
28 | #include "Timer.h" |
29 | #include <wtf/Deque.h> |
30 | #include <wtf/Function.h> |
31 | #include <wtf/WeakPtr.h> |
32 | |
33 | namespace WTF { |
34 | class Lock; |
35 | }; |
36 | |
37 | namespace WebCore { |
38 | |
39 | template <typename T> |
40 | class TaskDispatcher { |
41 | public: |
42 | TaskDispatcher(T* context) |
43 | : m_context(context) |
44 | { |
45 | } |
46 | |
47 | void postTask(WTF::Function<void()>&& f) |
48 | { |
49 | ASSERT(m_context); |
50 | m_context->postTask(WTFMove(f)); |
51 | } |
52 | |
53 | private: |
54 | T* m_context; |
55 | }; |
56 | |
57 | template<> |
58 | class TaskDispatcher<Timer> : public CanMakeWeakPtr<TaskDispatcher<Timer>> { |
59 | public: |
60 | TaskDispatcher(); |
61 | void postTask(WTF::Function<void()>&&); |
62 | |
63 | private: |
64 | static Timer& sharedTimer(); |
65 | static WTF::Lock& sharedLock(); |
66 | static void sharedTimerFired(); |
67 | static Deque<WeakPtr<TaskDispatcher<Timer>>>& pendingDispatchers(); |
68 | |
69 | void dispatchOneTask(); |
70 | |
71 | Deque<WTF::Function<void()>> m_pendingTasks; |
72 | }; |
73 | |
74 | template <typename T, typename C = unsigned> |
75 | class GenericTaskQueue : public CanMakeWeakPtr<GenericTaskQueue<T, C>> { |
76 | public: |
77 | GenericTaskQueue() |
78 | : m_dispatcher() |
79 | { |
80 | } |
81 | |
82 | GenericTaskQueue(T& t) |
83 | : m_dispatcher(&t) |
84 | { |
85 | } |
86 | |
87 | GenericTaskQueue(T* t) |
88 | : m_dispatcher(t) |
89 | , m_isClosed(!t) |
90 | { |
91 | } |
92 | |
93 | typedef WTF::Function<void ()> TaskFunction; |
94 | |
95 | void enqueueTask(TaskFunction&& task) |
96 | { |
97 | if (m_isClosed) |
98 | return; |
99 | |
100 | ++m_pendingTasks; |
101 | m_dispatcher.postTask([weakThis = makeWeakPtr(*this), task = WTFMove(task)] { |
102 | if (!weakThis) |
103 | return; |
104 | ASSERT(weakThis->m_pendingTasks); |
105 | --weakThis->m_pendingTasks; |
106 | task(); |
107 | }); |
108 | } |
109 | |
110 | void close() |
111 | { |
112 | cancelAllTasks(); |
113 | m_isClosed = true; |
114 | } |
115 | |
116 | void cancelAllTasks() |
117 | { |
118 | CanMakeWeakPtr<GenericTaskQueue<T>>::weakPtrFactory().revokeAll(); |
119 | m_pendingTasks = 0; |
120 | } |
121 | |
122 | bool hasPendingTasks() const { return m_pendingTasks; } |
123 | bool isClosed() const { return m_isClosed; } |
124 | |
125 | private: |
126 | TaskDispatcher<T> m_dispatcher; |
127 | C m_pendingTasks { 0 }; |
128 | bool m_isClosed { false }; |
129 | }; |
130 | |
131 | } |
132 | |